Wireless sensor networks refers to a group of spatially dispersed and dedicated sensors for monitoring and recording the physical conditions of the environment and organizing the collected data at a central location. WSNs measure environment conditions like temperature, sound, pollution levels, humidity, wind speed and direction, pressure, etc. In existing system, body mounted sensors were used which collects and stores data of human activities under the conditions of free living. Body-mounted sensors cannot detect the breath rate properly due to the problem that there is a deviation in the observed breath rate if the body is in motion. To overcome this, humidity sensor is used which detects and measures atmospheric humidity. And an electrical quantity such as capacitance or resistance varies along with the surrounding humidity and an output voltage or current corresponding to these fluctuations is produced. Relative humidity compares the moisture content in the air with the saturated moisture at the same temperature and pressure. In the earlier system, a human hair connected to a dial expanded and contracted with the relative humidity. These devices are used by calibrating to a dry atmosphere. GSM Module can use to display the message in mobile phone.